2:100 question regarding "modern" mode...

[myqqy]

I just picked up a 2:100 power amp to go with my rectifier recording preamp, and this is the first time i've gotten to use the modern mode on channel 2. There's a pretty noticable hum when i switch on the modern mode, and wonder how anybody else deals with that. Do people just live with it, or do people use some sort of hush unit for that? Any input would be appreciated...

 

[B@SZ]

Well, maybe youve got some tube problems, if not why dont you call mesa for some customer support, also I remember that sometimes modern mode gets noisy depending on how much gain your dialing in, if you dont like hush and noise try a Decimator, rackmount or Stompbox , both are great and they kill the annoying noise without sacrificing all that recto tone.

http://www.isptechnologies.com/decimatorproducts.htm

check the audio samples!

 

[myqqy]

Thanks for the info about the decimator- the tubes on this one are supposedly new, and i'm only getting that buzz on the modern mode- every other mode sounds pristine. I was wondering if other 2:100 owners have the same buzzing sound when they switch into modern mode..

 

[again with this]

No man. There should be no hum.

I run a G Major with a mild gate in the loop of my Recto Pre (to eliminate the signal coming from the Pre), and there is virtually zero speaker hum in modern mode coming from the power amp. the fan cooling the tubes is louder.

 

[myqqy]

Interesting- i just rewired everything so i'm going to do a few more tests and see what happens with the modern mode. I would certainly like it more if there was no extra hum attached!

 

[msi]

While in theory there should be no hum, it is possible. Whats happening is your sending a little bit of voltage from one device over to the ground of the amp. When the switch is open, that voltage is just sitting there, but when modern mode is engaged the voltage then has access to the ground of amp. It's probably not a tube issue as you would see the problem at all times, not just when modern mode is engaged. What you can do is stick a cable in the power amp, and then short the other end out by connecting the tip and sleeve. If the amp switches and there is no hum, you can be positive it's a ground loop. If so ground loops are very difficult to alleviate.

 

[myqqy]

Now there's an entirely new issue- it appears that the rectifier inputs on the 2:100 are not working at all. When i have my cables plugged into the rectifier inputs, the volume controls on the 2:100 do not work at all- they have no influence on the volume or tone. The gain controls on the rectifier recording preamp act as volume knobs, and the modern mode does not activate at all. Weird.
When i plug the cables into the normal inputs on the 2:100, everything works fine- so it must just be a problem with the rectifier inputs. Frustrating!! :x

 

[sixtonoize]

From the manual:

The RECTO INPUTS are wired such that when the companion Rectifier
Recording Preamp is used, the circuit remains exactly true to
the signal path between preamp and power section as it occurs in the Dual and Triple Rectifier Heads. To achieve this duplication,
a driver tube responsible for the effects return stage and all related circuitry in the 2:100 must be removed and this includes the
LEVEL Conbtrols as they are part of this circuitry. As a result, when using the RECTO INPUTS, you will use the Recto Pre LIVE
OUTPUT Control as your overall final master level control.

So it's not a problem. That's how it's supposed to work.

 

[myqqy]

I forgot reading that in the manual- but the modern mode is still not being engaged, and it's the gain knobs on the preamp that are acting as overall volume, and not the live output control on the preamp.